/* ==========================================================================
   Tribu Roadtrip 2027 — base.css
   Variables, reset, typographie, focus, accessibilité et utilitaires
   ========================================================================== */

:root {
  --bg: #06040f;
  --bg-2: #0e0a1f;
  --surface: #161033;
  --surface-2: #1a123a;
  --border: #3d2b7a;
  --border-soft: #231b42;
  --text: #ffffff;
  --text-soft: #e2e8f0;
  --muted: #94a3b8;
  --violet: #7b2cbf;
  --violet-deep: #7209b7;
  --violet-light: #c77dff;
  --violet-neon: #9d4edd;
  --magenta: #e024c3;
  --magenta-deep: #b5179e;
  --pink: #f72585;
  --grad-cta: linear-gradient(90deg, #7b2cbf 0%, #b5179e 100%);
  --grad-alert: linear-gradient(90deg, #f72585 0%, #7209b7 100%);
  --grad-page: linear-gradient(180deg, #06040f 0%, #0e0a1f 45%, #161033 100%);
  --radius: 12px;
  --radius-lg: 20px;
  --radius-pill: 999px;
  --shadow: 0 10px 30px rgba(0, 0, 0, 0.45);
  --glow: 0 4px 18px rgba(224, 36, 195, 0.35);
  --space-1: 0.5rem;
  --space-2: 1rem;
  --space-3: 1.5rem;
  --space-4: 2.5rem;
  --space-5: 4rem;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --max: 1120px;
}

/* Box-sizing reset */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  color-scheme: dark;
  scroll-behavior: smooth;
  font-size: 100%;
  overflow-x: hidden;
  max-width: 100vw;
}

body {
  background-color: #030208;
  color: var(--text-soft);
  font-family: var(--font);
  line-height: 1.6;
  min-height: 100vh;
  position: relative;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Arrière-plan optimisé GPU en format WebP (haute performance, zéro saccade) */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  background: url('../images/background.webp') no-repeat center center;
  background-size: cover;
  z-index: -10;
  pointer-events: none;
  transform: translate3d(0, 0, 0);
  will-change: transform;
}

/* Prévention stricte des décalages de mise en page (CLS - Cumulative Layout Shift) pour les icônes */
iconify-icon {
  display: inline-block;
  width: 1em;
  height: 1em;
  line-height: 1;
  vertical-align: -0.125em;
  contain: size layout;
}

/* Typographie responsive */
h1, h2, h3, h4 {
  color: var(--text);
  text-transform: uppercase;
  font-weight: 800;
  letter-spacing: 0.5px;
  line-height: 1.15;
}

h1 {
  font-size: clamp(2rem, 5vw + 1rem, 3.4rem);
  font-weight: 900;
  letter-spacing: 1px;
}

h2 {
  font-size: clamp(1.6rem, 3.5vw + 0.5rem, 2.3rem);
  margin-bottom: var(--space-2);
}

h3 {
  font-size: clamp(1.15rem, 2vw + 0.4rem, 1.4rem);
  margin-bottom: var(--space-1);
}

p {
  margin-bottom: var(--space-2);
}

p:last-child {
  margin-bottom: 0;
}

a {
  color: var(--violet-light);
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color 0.2s ease;
}

a:hover {
  color: #ffffff;
}

img, svg {
  display: block;
  max-width: 100%;
  height: auto;
}

/* Sur-titres */
.sur-titre {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 2px;
  color: var(--violet-light);
  margin-bottom: var(--space-1);
}

.text-muted {
  color: var(--muted);
  font-size: 0.875rem;
}

/* Focus visible accessible */
:focus-visible {
  outline: 3px solid var(--violet-light);
  outline-offset: 3px;
}

/* Lien d'évitement WCAG */
.skip-link {
  position: absolute;
  top: -60px;
  left: 1rem;
  background: var(--violet-deep);
  color: #ffffff;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius);
  z-index: 1000;
  font-weight: 700;
  text-decoration: none;
  transition: top 0.2s ease;
}

.skip-link:focus {
  top: 1rem;
}

/* Lecteur d'écran seul */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* Conteneur principal */
.container {
  width: 100%;
  max-width: var(--max);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--space-2);
  padding-right: var(--space-2);
}

@media (min-width: 768px) {
  .container {
    padding-left: var(--space-3);
    padding-right: var(--space-3);
  }
}

/* Motifs signature Triangles */
.tri {
  clip-path: polygon(50% 0%, 100% 100%, 0% 100%);
}

.tri-down {
  clip-path: polygon(0% 0%, 100% 0%, 50% 100%);
}

.section-divider {
  width: 100%;
  height: 36px;
  background: var(--surface);
  clip-path: polygon(0 0, 100% 0, 100% 40%, 50% 100%, 0 40%);
  margin: 0 auto;
}

/* Accessibilité: prefers-reduced-motion */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}